This project is concerned with the cellular basis of interferon production and hyporeactivity to interferon production. Interferon is produced by B and T lymphocytes. The question is whether its properties vary because of the cell origin or because of the inducer. Hyporeactivity may depend on which cell is induced by the first inducer. This hypothesis remains to be rigorously tested. In addition, the role of hyporeactivity factor on B, T lymphocytes and macrophages will be tested.